Halogenhalogen interactions in decahalo-closo-carboranes: CSD analysis and theoretical study

The ability of decachloro, decabromo and decaiodo ortho, meta and para-closo-carboranes to establish "like-like" halogenhalogen interactions is evaluated in this study using the PBE0-D3/def2-TZVP level of theory. We have used three decahalocloso isomers (ortho-, meta-, and para-) and computed both homodimers and heterodimers. The resulting dimerization energies (B-XX-B) are moderately strong. Furthermore, we have used Bader's quantum theory of "atoms in molecules" (QTAIM) to characterize the type I/II halogenhalogen interactions described herein. Moreover, several examples retrieved from the Cambridge Structural Database (CSD) are also highlighted to show the ability of decahalo-closo-carboranes to participate in "like-like" halogen bonds.